Combination thermostatic switch and electric connection plug



Sept. 13, 1932. M s. RUNSVOLD 1,875,763

COMBINATION THERMQSTATIC SWITCH AND ELECTRIC CONNECTION PLUG Filed Sept. 25. 1950 figig emola 4497/ max/010 a i 17 45 BY 2 20 f v Patented Sept. 13, 1932 PATENT" OFFICE MARTIN S. BUNSVOLD, OF SAN DIEGO, CALIFORNIA COMBINATION THEBMOSTATIC SWITCH AND ELECTRIC CONNECTION PLUG Application filed September 25, 1930. Serial No. 484,324,

My invention relates to combination thermostatic switch and electric connection phfig, and the objects of my invention are:

irst, to provide a plug of this type which I when connected to a heating device, such as an electric iron, breaks the circuit when the temperature of the heating device reaches a pre-determined point; v

Second, to provide a device of this class in which the contact is broken instantaneously,

thereby reducing arcing to a minimum;

Third, to provide an electric connection plug of this type which has incorporated therewith a manually operated switch as well as a thermostatic switch so that the plug need not be removed from the heating device but may remain thereon;

Fourth, to provide an electric connection plug of this type which is particularly compact; and

Fifth, to provide an electric connection plug of this type which is durable, eificient in its action, and which will not readily deteriorate or get out of order.

With these and other objects in view as will appear hereinafter, my invention con sists of certain novel features of construction, combination and arrangement of parts and portions as will be hereinafter described in detail and particularly'set forth in the appended claims, reference being had to the accompanying drawing and to the characters of reference thereon, which form a part of this application, in which:

Figure 1 is an elevationalview of'my novel electric connection plug with the cover casing removed, exposing the mechanism within the plug; Fig. 2 is a sectional view through 2--2 of Fig. 1, with the casing members shown in dotted outline; Fig. 3 is a plan view of the automatic or thermostatic switch in its off position and with adjacent portions of the plug mechanism shown fragmen- 5 tarily; Fig. 4 is a sectional view of the toggle switch mechanism removed from the plug casing; and Fig. 5 is a transverse, sectional view through the plug taken substantially along the line 5--5 of Fig. 1.

Similar characters of reference refer to similar parts and portions throughout the several views of the drawing.

Base casing 1', cover casing 2, conductor 3, terminal member 4, toggle switch body member 5, trip arm 6, switch knob 7, contact lever 8, contact lever shifting member 9, spring 10, conductor 11, terminal member 12, contact spring 13, heat conductor 1 1, thermostat element 15, support member 16, contact shifting lever 17 toggle arm 18, spring 19, and push 0 button 20 constitute the princlpal parts and portions. of my combination thermostatic switch and electric connection plug.

A base casing 1 and cover casing 2 are provided. These casings are complementary halves. The entire mechanism of the switch is mounted on the inner side of the base casing 1. The inner side of this casing is provided a little above its central portion with a depression 1a, and terminal receiving channels communicating therewith, in WhlCh are mounted the terminal members of the plug. The channels 1?) are in parallel disposed re lation to each other and communicate with the lower end of the base casing 1.

The cover casing 2 is provided with complementary depressions and channels. I

Secured to the upper portion of the casing 1, is an end of a conductor 3, which extends across the depression 1a, and is curved to clear other mechanism described hereinafter. The lower end of the conductor 3 is attached to a terminal member 4 mounted in one of the channels 1?).

The first-mentioned or upper end of the 35 conductor 3, is provided with a screw 3a, whereby the one wire of an electric conductor cord may be attached This cord passes out a channel 10, which, with a complementary channel in the cover casing, forms an openmg.

The lower portions of the casings 1 and 2 are constricted slightly so as to conform to the cross section of the conventional electric connection plug. The depression 1a is formed above the constricted portion. Along the one side of the depression 1a the casings are protruded slightly to form space for a toggle switch mechanism.

The toggle switch mechanism includes a toggle switch body member 5. This body member is substantially of V-shaped plan, with the apex portion adjacent the protruding side of the casing; the leg portions thereof diverging inwardly towards the opposite sides of the plug.

The body member comprises an upper and lower V-shaped portion 5a and 5b, which are connected together, and held in parallel disposed relation by vertically extending web portions 50, which join the extended inward ends of the leg portions, shown best in Fig. 4. The lower V-portion 5b is provided with a pair of arcuately extending and downward 1y ofiset lug portions 5d, which are riveted or otherwise secured to the casing. The lug portions space the lower V-portion 5b slightly above the door of the depression 1a.

At the apex of the V-shaped portions 505 and 56, there are provided oppositely disposed openings 56, which form bearings. Journaled in the openings 56, by means of lugs 6a on its upper and lower sides, and extending inwardly between the V-portions 5a: and 5b, is a trip arm 6. The trip arm is adapted to oscillate about the axis of the lug 6a, and is limited in its movement by stop portions 5/, which are extruded from the ii-portions 5a and 5b. The trip arm 6 extends outwardly through a notched portion 10 provided in the side walls of the casing 1, which, with the corresponding notch portion in the casing 2, forms an opening communicating with the depression 1a. This outer end of the trip arm 6 is moulded within a switch knob 7, which protrudes from the casing, as shown in Fig. 1, where it may readily shift from one position to another by pressure of ones thumb.

A contact lever 8 is provided. This member is of substantally U-shaped form; its leg portions 8a are provided at their extended ends with openings. Formed on the outer sides of the V-portions 5a and 5b of the body member 5, at the apexes thereof, and inwardly from the openings 5e, are projections, which form journals 59 for the above-men tioned openings.

The leg portions 8a of the contact lever 8 are offset so as to engage the inner edges or" the li -portions 5a and 5?) so as to limit the arcuate movement of the contact levers. The extended end or cross portion 86 of the contact lever is provided with a channel or depression intersected by an opening 80. A contact lever shifting member 9 is provided, which extends through the openings 80, and is provided with a head portion 9a adapted to normally fit in the channel or depression intersected by said opening.

The other or outer end of the support shift-- member 9 is bifurcated, as indicated by 9?). The trip arm 6 extends towards this bifurcated end portion 95, and is provided with a slot near its end, leaving a journal pcition,

. rangement, movement of the switch knob 7 which fits in the notch between the bifurcations of the end 9b.

The bifurcated end portion 9b forms a shoulder with the shank portion, designated 90, of the contact lever shifting member, against which rests the one end of the spring 10, the other end of which bears against the cross portion connected to the ends of the legs 8a of the contact lever. With this arand trip arm 6 acts against the contact lever until past the center whereupon the expansion of the spring causes the contact lever to snap to its other extreme position, as shown by dotted lines in Fig. 1. I

Secured by one end in the upper portion of the casing 1 is a conductor 11, which extends from said upper corner portion towards the extremity of the contact lever 8 when in the position shown by the solid lines in Fig. 1. This end of the conductor ll'overhangs the depression 1a, and is resilient so as to yieldably engage the extended portion of the contact lever B when in its upper position, thus forming a contact portion 11a. The first- Inentioned end of the contact 11 is provided with a screw 116, to which is attached the other end of an electric wire cord, not shown.

Extending outwardly and downwardly from the cross portion 86 of the contact lever 8 is a contact tongue 8d.

Mounted in the remaining terminal. receiving channel is a terminal member 12 similar in construction to the terminal member 4. The terminal member 12 is secured to a spring contact 13, which extends from the terminal member upwardly and inwardly from the terminal into engageable relation with the contact tongue 8d when said tongue is in the solid line position shown in Fig. 1. Also, secured to the terminal 12 or made integral therewith, is a heat conductor 14, which extends in ofiset relation therewith between the two terminals to a point near the lower end of the casing.

The heat conductor 14 is provided at its lower extremity with a lip portion 14a, which lies fiat in respect to the plane between the two casings l and 2, and in slight depressions formed in said casings. Secured to the lip portion 14a is the lower end of a thermostat element 15, the extended end of which projects over the depression 1a, and is distortable towards and away from the floor of said depression.

Extending longitudinally across the iioor of the depression 1a, and near the opposite side thereof from the toggle switch niec anisrn is a support member 16, having an turned upper end 16a. Rotatably mounted at or near the lower end or the support her is a lever arm 17, which extends npwta o3 therefrom. At its upper portion the is is provided with an inwardly extending hook p tion 170:, which points towards the conisa adapted to engage the extended end of the thermostat element 15, this extended end being reduced in cross section.

The contact spring 13 is provided with a loop portion 13a, which fits over the upturned end of the hook portion 17a between thermostat elements and the horizontal portion of the arm 17a, as shown in Figs. 1, 2, 3, and 5. WVhen free of the contact tongue 8d, the loop 13a of the contact spring 13 pulls inwardly on the hook portion 17 a of the lever 17, thus, when engaged by the contact tongue 8d it fits loosely over the upturned portion 17a.

Pivotally secured to the extended upper end of the lever 17 is a toggle arm 18, which is provided with a constricted shank portion 18a arranged to extend through an opening in the upturned end 16a of the support member 16. A spring 19 bears against a shoulder formed at the beginning of the shank portion 18a and against the upper end 16a so that when the connection between the toggle arm 7 is ofiset outwardly with respect to the connection of the lever 17 with the support 16, said spring and toggle member tend to cause counterclockwise rotation of the contact shifting lever 17. This counterclockwise movement is limited by a stop 16?) provided on the support 16.

Connected to the extended portion of the shifting lever 17 is a loop portion 20a at the inner end of a push button 20. The push button tits in a notch 1d provided in the casing 1.

Operation of the thermostatic mechanism is as follows: Heatjrom the electric iron or other heating device is transmitted through the heat conductor 14 to the thermostat element 15, which causes the extended end of the thermostat element 15 to distort in the direction of the arrow shown in Fig. 5, so as to. move clear of the upturned end of the arm 17a, whereupon the spring 19 causes counterclockwise movement of the contact shifting lever 17. In so moving, the upturned arm 17 a pulls on the loop 13a and shifts the contact spring 13 clear of the contact tongue 8d, as shown in Fig. 3. The under side of the extended portion 15a of the thermostat element is beveled so that when the contact shifting lever has moved into the position shown in Fig. 3, said thermostat elem'ent is free to return to its normal position.

The switch is reset by pushing in on the push button 20 until the contacting lever is in the position shown in Fig. 1 and again interlocked with the thermostat element. Manual control of the circuit to the heating device attached to the plug is effected by the toggle switch mechanism, of which the switch knob Tforms a part. Any suitable means may be provided for effecting adjustment of the termostat element.

Though I have shown and described a particular construction, combination and arrangement of parts and portions, I do not wish to be limited to this particular construction, combination and arrangement, but desire to include in the scope of my invention the construction, combination and arrangement substantially as set forth in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: Y

1. A combination thermostatic switch and electric connection plug consisting of 3. casing, terminals therein arranged to connect to an electric element, a pair of contacts within said casing, the one of said contacts connected to one lead of an electric circuit, the other of said contacts connected with one of said terminals, yieldable means tending at all times to separate the said contacts, and a thermostat element adapted to receive heat transmitted to said terminals, said thermostat element arranged to engage and restrain the action of said yieldable means, whereby said contacts are normally in engagement with each other.

2. A combination thermostatic switch and electric connection plug consisting of a terminal element arranged to connect with an electric heating element,-a conductor joined to a lead of an electric circuit, contact means normally connecting said conductor with said terminal, yieldable means tending at all times to separate said contact means, a thermostat element arranged to receive heat from said terminal, said thermostat element normally extending into engageable relation with said yieldable means for normally restraining said means from acting upon said contact.

3. In a device of the class described, a casing, a terminal therein arranged to connect with an electric heating element, a conductor therein arranged to connect with the lead of an electric circuit, contact members joining said conductor to said terminal, yieldable means arranged to separate said contact members, a thermostat element arranged to receive heat from said terminal, and extending into engageable relation with said yieldable means, said yieldable means arranged in remote relation with the hotter portion of said thermostat element, said thermostat element arranged to normally restrain said yieldable means from acting upon said contact members due to engagement of said contact.

4. In a device of the class described, a casing, terminals therein arranged to connect to an electric element, a pair of contacts within said casing, the one of said contacts connected to one lead of an electric circuit, the 1 other of said contacts connected with one of said terminals, yieldable means tending to separate the said contacts, a thermostat element adapted to receive heat transmitted to said terminals, said thermostat element arranged to restrain the action of said yieldable means, whereby said contacts are normally in engagement with each other, and switch means within said casing arranged to separate the said contacts independently of said thermostatic element.

5. In a device of the class described, a casing, a terminal therein arranged to connect with an electric heating element, a conductor therein arranged to connect with the lead of an velectric circuit, contact members joining said conductor to said terminal, yieldable means arranged to separate said contact members, a thermostat element arranged to receive heat from said terminal, and extending into engageable relation with said yieldable means, said yieldable means arranged in remote relation with the hotter portion of saidthermostat element, said thermostat element arranged to normally restrain said yieldable means from acting upon said contact members due to engagement of said contact, and switch means within said casing arranged to separate the said contacts independently of said thermostatic element.

6. In a device of the class described, a casing, a terminal therein arranged to connect to the one end of an electric heating element, a conductor arranged to join to the one lead of an electric circuit, contact means including two elementsijoining said terminal with said conductor, manual means operatively associated with one element of said contact means for effecting separation of said contact means, and thermostatic means operatively associated with the other of said contact means also arranged to separate the said contact means, and means for conducting the heat of said electric heating element to said thermostatic means. 7. In a device of the class described, a casing, a first and asecond terminal therein, said terminals arranged to join to an electric heating element, said first terminals connected to the one lead of an electric circuit, a pair of contacts, an intermediate contact means joining said contacts, a switch means for shifting said intermediate contact out of and into engagement with said contacts, yieldable means tending to separate one of said contacts from said contact means, and a thermostat element associated with the second of said terminals for receiving heat therefrom, said thermostat element engageable with said yieldable means for normally restraining the same and permitting contact between said one contact and said contact means.

8. In a device of the class described, arranged to be inserted in an electric circuit between a lead and a heating element, a. casing, a terminal, a conductor, contacts associated with said terminal and said conductor, and intermediate contact means joined to both of said contacts, a manual switch means arranged to shift said intermediate contact free from or into engagement with said contact, yieldable means tending to separate one of said contacts from said intermediate contact means, and a thermostat element normally restraining the action of said yieldable means, whereby said contact normally engages said intermediate contact.

In testimony whereof, I have hereunto set my hand at San Diego, California, this 17th day of September, 1930.

MARTIN S. RUNSVOLD.

ioa 

